Remove unnecessary RuntimeContext data/frame split

Author: theodorejb

src/Compiler.php

@@ -94,8 +94,7 @@ private static function templateClosure(string $code, string $partials = '', str
         $use = $useVars !== '' ? " use ($useVars)" : '';
         return <<<PHP
             function (mixed \$in = null, array \$options = [])$use {
-             \$cx = LR::createContext(\$in, \$options, [$partials]);
-             \$cx->frame['root'] = &\$cx->data['root'];$stmts
+             \$cx = LR::createContext(\$in, \$options, [$partials]);$stmts
              return $code;
             }
             PHP;
@@ -819,7 +818,7 @@ private function getSimpleHelperName(PathExpression|Literal $path): ?string
     private function buildBasePath(bool $data, int $depth): string
     {
         if ($data) {
-            return '$cx->frame' . str_repeat("['_parent']", $depth);
+            return '$cx->data' . str_repeat("['_parent']", $depth);
         }
         return $depth > 0 ? "\$cx->depths[count(\$cx->depths)-$depth]" : '$in';
     }

src/HelperOptions.php

@@ -97,12 +97,12 @@ private function invokeBlock(\Closure $closure, mixed $context, mixed $data): st
         // HBS.js options.fn(this) / options.inverse(this)), since the scope level isn't changing.
         $pushDepths = $context !== $scope;
         $resolvedContext = $pushDepths ? ($context === Scope::Use ? $scope : $context) : $scope;
-        $savedFrame = null;
+        $outerFrame = null;
         $bpStack = null;
 
         if (isset($data['data'])) {
-            $savedFrame = $cx->frame;
-            $cx->frame = $data['data'];
+            $outerFrame = $cx->data;
+            $cx->data = $data['data'];
         }
 
         if (isset($data['blockParams'])) {
@@ -119,8 +119,8 @@ private function invokeBlock(\Closure $closure, mixed $context, mixed $data): st
         if ($pushDepths) {
             array_pop($cx->depths);
         }
-        if ($savedFrame !== null) {
-            $cx->frame = $savedFrame;
+        if ($outerFrame !== null) {
+            $cx->data = $outerFrame;
         }
         $cx->inlinePartials = $savedInlinePartials;
         return $ret;
@@ -154,7 +154,7 @@ public function iterate(array $items): string
         $last = count($items) - 1;
         $ret = '';
         $i = 0;
-        $outerFrame = $cx->frame;
+        $outerFrame = $cx->data;
         // Pre-allocate bpStack once; mutate [0][0] and [0][1] per iteration.
         // PHP COW ensures the inner array's refcount returns to 1 after $cb() returns,
         // so the next iteration's assignment is an in-place mutation, not a copy.
@@ -166,7 +166,7 @@ public function iterate(array $items): string
             $data['key'] = $index;
             $data['index'] = $i;
             $data['last'] = $i === $last;
-            $cx->frame = $data;
+            $cx->data = $data;
 
             $bpStack[0][0] = $value;
             $bpStack[0][1] = $index;
@@ -175,7 +175,7 @@ public function iterate(array $items): string
             $i++;
         }
 
-        $cx->frame = $outerFrame;
+        $cx->data = $outerFrame;
         array_pop($cx->depths);
         $cx->inlinePartials = $savedInlinePartials;
         return $ret;

src/Runtime.php

@@ -169,31 +169,33 @@ public static function lookupLength(mixed $base, bool $strict = false): mixed
     public static function createContext(mixed $context, array $options, array $compiledPartials): RuntimeContext
     {
         $parentCx = self::$partialContext;
-        $root = ['root' => $context];
 
         if ($parentCx !== null) {
             // Partial context: reuse the parent's already-merged helpers and partials directly.
-            // PHP copy-on-write ensures inlinePartials is only copied if in() registers a new inline partial.
-            // Inherit the parent's current frame so @index, @key, etc. remain accessible inside partials.
-            // templateClosure will update frame['root'] to reference this partial's own data['root'].
+            // PHP copy-on-write ensures inlinePartials is only copied if fn() registers a new inline partial.
+            // Inherit the parent's current data so @index, @key, etc. remain accessible inside partials.
+            // Unset 'root' first to break the reference established by `$in = &$cx->data['root']` in the
+            // calling template; a direct assignment would write through it and corrupt the caller's $in.
+            $data = $parentCx->data;
+            unset($data['root']);
+            $data['root'] = $context;
             return new RuntimeContext(
                 helpers: $parentCx->helpers,
                 partials: $parentCx->partials,
                 inlinePartials: $parentCx->inlinePartials,
                 depths: $parentCx->depths,
-                data: $root,
-                frame: $parentCx->frame,
+                data: $data,
                 partialBlock: $parentCx->partialBlock,
             );
         }
 
         $data = $options['data'] ?? [];
+        $data['root'] = $data['root'] ?? $context;
         $extraHelpers = $options['helpers'] ?? [];
         return new RuntimeContext(
             helpers: $extraHelpers ? array_replace(Runtime::defaultHelpers(), $extraHelpers) : Runtime::defaultHelpers(),
             partials: array_replace($compiledPartials, $options['partials'] ?? []),
-            data: ['root' => $data['root'] ?? $context],
-            frame: $data,
+            data: $data,
         );
     }
 
@@ -316,7 +318,7 @@ public static function sec(RuntimeContext $cx, mixed $value, mixed $in, ?\Closur
         // with no arguments, mirroring HBS.js which does not treat them as helper calls.
         if ($value instanceof \Closure) {
             $result = $helperName !== null
-                ? $value(new HelperOptions(scope: $in, data: $cx->frame, cx: $cx, cb: $cb, inv: $else))
+                ? $value(new HelperOptions(scope: $in, data: $cx->data, cx: $cx, cb: $cb, inv: $else))
                 : $value();
             return static::resolveBlockResult($cx, $result, $in, $cb, $else);
         }
@@ -473,7 +475,7 @@ public static function hbch(RuntimeContext $cx, \Closure $helper, string $name,
         if ($numParams === 0 || $numParams > count($positional)) {
             $positional[] = new HelperOptions(
                 scope: $_this,
-                data: $cx->frame,
+                data: $cx->data,
                 cx: $cx,
                 name: $name,
                 hash: $hash,
@@ -497,7 +499,7 @@ public static function hbbch(RuntimeContext $cx, \Closure $helper, string $name,
     {
         $positional[] = new HelperOptions(
             scope: $_this,
-            data: $cx->frame,
+            data: $cx->data,
             cx: $cx,
             name: $name,
             hash: $hash,

src/RuntimeContext.php

@@ -13,15 +13,13 @@ final class RuntimeContext
      * @param array<string, \Closure> $inlinePartials block-scoped {{#* inline}} partials (reset on fn() return)
      * @param array<mixed> $depths
      * @param array<mixed> $data
-     * @param array<mixed> $frame
      */
     public function __construct(
         public array $helpers = [],
         public array $partials = [],
         public array $inlinePartials = [],
         public array $depths = [],
         public array $data = [],
-        public array $frame = [],
         public ?\Closure $partialBlock = null,
     ) {}
 }